A BBC-funded film about the Rwandan genocide billed as an 'authentic re-creation' of a real-life story, is facing criticism for exacerbating the trauma experienced by genocide survivors.

Backed by the Rwandan government, shot on location in the country and to be premiered there this week, Shooting Dogs was intended to raise awareness of the conflict. Aid organisations are now saying that it was a shot with a lack of sensitivity so soon after the events.

The film, which stars Hugh Dancy and John Hurt, tells the story of a massacre at a school, L'Ecole Technique Officielle, during the genocide in 1994. It includes scenes in which machete-wielding Interahamwe militia close in on the building, hacking women and children to death. It was filmed where the atrocity took place, using many local people, including genocide survivors, as extras and members of the crew.

Aid workers have expressed concern that some local people were traumatised by witnessing the reconstruction. On one occasion, students from a nearby school had to be taken to hospital and sedated when they suffered flashbacks after overhearing the chants and whistles of the angry mob. One member of the crew suffered a breakdown when he was taken back to the street where he had been forced to hide down a manhole for three months to escape the killers.

'In Rwanda, if you see a machete being wielded it doesn't matter if it's for a film - it seems real,' said Mary Kayitesi Blewitt, director of the UK-based Rwandan charity Survivors' Fund. 'When the shoot was over, we had to step up trauma counselling. It took some people six months to overcome the anxiety, fear and paranoia.'

Like two other recent films about the genocide - Sometimes in April and Hotel Rwanda - Shooting Dogs is due to be screened in Kigali this month.

'We're providing pamphlets and counselling to prepare people for seeing it,' said Blewitt. 'What really hurts is that the BBC will be making money from the film, but it has not put a penny into the organisations dealing with all this.'

A Unicef spokesman said: 'It's important to highlight issues like the Rwandan conflict, but reliving these experiences can be traumatic for children and we encourage journalists and others who work with survivors to adhere to our guidelines.'

David Belton, who wrote and produced Shooting Dogs, said that he 'deeply regretted' the incident with the students. 'We took great pains to avoid local people being confronted with the disturbing scenes, and had two trauma counsellors and medical staff on hand.

'I have been in close communication with the Rwandan government and organisations working there since we left, and none of them has mentioned any subsequent problems. We made the film in Rwanda because the Rwandans wanted us to. They were appalled that Hotel Rwanda was filmed in South Africa, with South African actors.'

Helen Bamber, director of the Helen Bamber Foundation for conflict survivors, criticised the decision not to vet any of the extras about their involvement in the 1994 massacre. Those who were likely to have perpetrated the killing, mainly from the Hutu tribe, were cast alongside their Tutsi victims. 'Who knows what kind of emotions that stirred up for the victims, and what kind of tensions it left behind?'

· Linda Melvern, author of A People Betrayed: The Role of the West in Rwanda's Genocide, argues in The Observer today that the film is inaccurate and misrepresents the BBC's role in reporting the atrocities. David Thompson, head of BBC Films, disputed this. 'As with all dramas there is some degree of artistic licence.'